Black Bulldogs
are the most common of the 4 Rare Colors in AKC English Bulldogs. The
black should be shiny & look black against black objects or in the sun
unless the seal gene is involved which can show a different color
undertone to the black coat. These dogs may or may not have a fawn
undercoat when the hair is rubbed backwards. The nose, footpads, &
eyeliner are always a true black.

As in all the Tri Colors (3 colors on
the dog one of which is always the tan points), the tan points
are typically on the eyebrows, cheeks, front shoulders (right
above the chest area between the legs), around the tail, and
partial on both front & back legs. Tan points will not show up
if the dog is white where the points would normally be. Tan
points can also be hidden by other genes, such as the SEAL gene,
as it is higher on the hierarchy of genes. Tan points can bleed through
on some dogs when only one [at] is present. It normally takes a
double [atat] dog to show tan points. As of this writing, the
geneticists do not know why this happens on some dogs with the
same dna & not others.

It is my thinking that Sable EB's that
show tan points &/or have dark etching, DO carry one [at] & are
ayat in their dna. A TRUE Fawn (red based dog) will not show sable hairs, tan
points, or dark etching & will be ayay in their DNA. To back
this up, we conducted a private study to back up our thinking.

Straight from the Scientists at UCDavis. Remember, even
the scientists have to add info, &/or make corrections from time
to time as new science is uncovered involving color genes in
dogs.

First let me say that this writing will be based on the
lettering that UCDavis uses for results. This is important,
because a lot of people use Vet Gen and their lettering for the
same results is different, which can be very confusing. ALSO, we
are completely leaving out the brindle pattern on dogs for this
discussion, because they can be (K), but the below statements
will not always apply to them. There is much more study needed
to figure out the brindle pattern in dogs.

As we all know, the color genes are in order of
dominance. The dominant black (k) gene comes before the
recessive black (a) gene, so if (K) is present, even just one,
the genes at agouti will NOT present on the dog. Although the
genes at agouti can be passed on, they will not show on the dog
passing them if (K) is present.

1st point: (K) is a Dominant Gene, so unlike the other
color genes, you need only one side to be (K) in order for the
dog to be black. So all our black dogs (the ones that are black
from this particular gene), can be either (KK) or (KN) and will
present as black dogs. Again, these dogs block anything at
agouti. This is why there has been much confusion as to why some
black to black matings have produced standard color puppies. Say
both parents are (KN), and both pass the (N) side to the same
puppy. Then you would have a fawn based puppy, not a black based
puppy.

2nd point: I love this one! If your dog is (KK), then
EVERY puppy this dog produces will be black (or black based) no
matter what the other parent. I have to test this out! But, I am
now wondering if this is why Chroma (our black & tan Stud) has
had ONLY Black & Tan/Black Tri puppies from EVERY litter he has
thrown so far, with all different color Moms. We will be doing
DNA on him to see if he is (KK).

3rd point: What about the agouti? The only way this can
present on your dog is he/she is (NN) at dominant black. (NN)
allows whatever the dog is at agouti to show on the dog. You
would think that if the dog was (NN) it would be fawn in color
or red based. BUT, if the dog is (NN-atat), Black & Tan, at
agouti, then this dog would be black based from agouti & would
therefore present as black & tan or black tri as some call it
when white is present. If the dog is (NN-ayat) at agouti, then
the dog would present as fawn or red based.

4th point: This is concerning the dog that is (NNayat).
Since the agouti is recessive, you need to have both sides for
the color to present. BUT, for some reason, (ayat) dogs can show
some tan points, because the tan points can “Bleed Through”, and
show on the dog.

5th point: When I speak of black (black based), and
fawn (red based) dogs in this writing, remember that the other
genes apply here too. For instance, if a dog is produced that is
(dd), blue, then all the info above would apply as to whether
this dog will be True Blue (black based), or Blue fawn (red
based).

Author: Rare Bulldogs 9-21-12

2014
DOMINANT BLACK-SEAL-K GENE

The genes that cause dogs to be SEAL are still not fully
understood by even the Scientists themselves. What we do know so
far, is that one of the K genes, (there are 3 series that we
know of on the K gene) specifically Kb seems to be responsible
for the seal coloring, which can be Black Seal, Chocolate Seal,
Blue Seal, or Lilac Seal. These dogs shine through a different
color, usually red, but can be fawn, gray, or even green shades,
from under the coat, especially in the sun. They are most always
only 2 colors, the second color being white, as this particular
K gene HIDES the color at agouti, so any tan points if present
will be hidden. True SEAL dogs will DNA [KbN ayay][KbN ayat][KbN atat][KbKb ayay][KbKb ayat][KbKb atat].Note: some labs will
render results of a Kbr dog as Kb, which is NOT SEAL but
Brindle.

The K gene has 3 parts to it.It is a
modifier gene, not a color gene. Which means it tells some of
the other genes on the hierarchy how to act...whether they can
show on the dog or not. This is what the geneticists at UCDavis
related to me: Kbr is associated with brindle, Kb is associated
with black, and Ky or N is associated with fawn.

Not to make this any harder but the Kb or
self-color gene is not only modified by the b and d dilution
genes but also the Kbr, and the Agouti locus. They change the
shade of the coat color. If a dog is KB, Kbr the
seal coat will have a darker color and some seals even look pure
black and white. If they are Kb, Ky and ayay in the A Locus they
would have been a fawn or red dog, so the fawn or red background
changes the color shade of the coat. This is why the seals can
look different shades of colors.

The K Gene is confusingly called the Dominant
Black Gene. This is confusing because only one part (of the 3
parts) of the K gene, specifically the Kb part, will render
Black or black base on a dog. The other 2 parts render brindle
or fawn/sable on the dog. That being said, the Dominant part is
correct in that the dog needs only ONE Kb to show black or black
base.

To Rare Color Breeders, this is VERY
important, important on 2 ends of the spectrum. The first is
positive in that the dog can have black & black based dogs with
ANY female even if she does not carry color. The second not so
positive is that this only happens 50% of the time, so only
apprx. 50% of the litter will be black or black based. To add to
that even the SEAL dogs that carry Black & tan [ayat] at agouti
will still have some fawn/sable/brindle puppies in the litter.
Each Black gene is only a 50/50 chance on every puppy. If you
are breeding to a double [atat] dog, this can eliminate your
double [atat] dogs100% chance of having all
black or all black based litters, you still render
fawn/sable/brindle in the litter and this goes down to 25% in
fawn/sable/brindle dogs when bred to a SEAL.

My point: You need to ask for
dna of both black genes when breeding to a SEAL dog. Why would
you breed down (dna wise that is) with your [atat] dog, and cut
your chances of black or black based puppies even more when
using a fawn/sable/brindle mate, especially on your females. Our
EB females will at best give us 4 litters & most of the time
only 3 if they are not over bred. Don’t eliminate the number of
your possible true color productions by breeding the wrong DNA.

The only way to avoid the above scenario is
to breed to a double [atat] dog or if you need the SEAL in your
program,use one that is also double [atat]….KbN
atat, not KbN ayay, or KbN ayat. You would get ALL black & black
based puppies this way. Also, when breeding your ayat
fawn/sable/brindle dogs with a double [atat] SEAL it increases
your chances of getting the full black base from 25% to 75%,
because a double [atat] SEAL dog throws black at 150%.

Copyright Rare Bulldogs 2014
Author Alesia Dixon
No permission to copy, reprint, or use in any way without
permission from the Author.